Airway dimensions and mandibular position in adults with different growth patterns: a cone-beam computed tomography study

Introduction
Orthodontic treatment modalities depend on individual patient’s growth pattern and mandibular position. The airway is an important determinant of treatment. Therefore, a clear correlation between different growth patterns, mandibular positions, and airway would lead to better diagnosis and more specific planning.

Objectives
The aim of this study was to evaluate mandibular position and its’ relationship to pharyngeal airway dimensions in patients with different growth patterns using cone-beam computed tomography (CBCT).

Material and methods
CBCT scans of patients were assigned to vertical, average, and horizontal growth pattern types, based on angular (S-N/Go-Me) and linear (S-Go/N-Me) measurements. Data of included patients was used for 3-dimensional reconstruction of the pharyngeal airway to assess parameters, such as total airway volume, airway length, mandibular position, and correlation with different growth patterns. For statistical analysis, one-way ANOVA, post-hoc Tukey test (for pairwise comparisons), and Spearman’s correlation with a significance level of 0.05 were applied.

Results
The mandibular distance from the airway was significantly higher in the horizontal growth pattern group (p = 0.035). Airway volume was lower in the vertical growth pattern group as compared with the horizontal growth pattern group (p = 0.043). A negative correlation was observed between mandibular position and airway length (p = 0.021, r = –0.338).

Conclusions
Subjects with horizontal growth patterns tend to have shorter and wider airways with their mandibles farther away, as compared to those with vertical growth patterns. To avoid the risk of compromising narrow airway dimensions, clinicians must take into account these findings while planning orthodontic and surgical treatment.